duplicate rows in QStandardItemModel in Qt - c++

Question

I'm trying to achieve something I though would be easy but cannot figure how to make it work.
In this basic example, I'm creating an address book, a single person can be in 2 groups, John Doe is a friend, but also a work colleague.
If I change his phoneNumber inside the friend group, it should also change in the work group.
This is how I first tried this with static content (in the end it is linked to a db)
addressBookListModel = new QStandardItemModel(0, 4);
addressBookListModel->setHeaderData(0,Qt::Horizontal,"First Name", Qt::DisplayRole);
addressBookListModel->setHeaderData(0,Qt::Horizontal,"fn", Qt::UserRole);
addressBookListModel->setHeaderData(1,Qt::Horizontal,"Last Name", Qt::DisplayRole);
addressBookListModel->setHeaderData(1,Qt::Horizontal,"ln", Qt::UserRole);
addressBookListModel->setHeaderData(2,Qt::Horizontal,"E-Mail", Qt::DisplayRole);
addressBookListModel->setHeaderData(2,Qt::Horizontal,"mail", Qt::UserRole);
addressBookListModel->setHeaderData(3,Qt::Horizontal,"Phone Number", Qt::DisplayRole);
addressBookListModel->setHeaderData(3,Qt::Horizontal,"phone", Qt::UserRole);
Then inserting the data :
//Group 1
QStandardItem * work = new QStandardItem("Work");
QList<QStandardItem*> workgroup;
workgroup << work ;
addressBookListModel->appendRow(workgroup);
//group 2
QStandardItem * friends = new QStandardItem("Friends");
QList<QStandardItem*> friendgroup;
friendgroup << friends ;
addressBookListModel->appendRow(friendgroup);
//One contact in both groups
QStandardItem * fn = new QStandardItem("John");
QStandardItem * ln = new QStandardItem("Doe");
QStandardItem * mail = new QStandardItem("john.doe#gmail.com");
QStandardItem * phone = new QStandardItem("[phone]");
QList<QStandardItem*> rowitems;
rowitems << fn << ln << mail << phone;
work->appendRow(rowitems);
friends->appendRow(row items);
but this only inserts john doe inside work like this :
I Thought this would be because row items is not a pointer, so I tried it this way :
//One contact in both groups 2
QStandardItem * fn = new QStandardItem("John");
QStandardItem * ln = new QStandardItem("Doe");
QStandardItem * mail = new QStandardItem("john.doe#gmail.com");
QStandardItem * phone = new QStandardItem("[phone]");
QList<QStandardItem*> rowitems;
rowitems << fn << ln << mail << phone;
QList<QStandardItem*> rowitemsB;
rowitemsB << fn << ln << mail << phone;
work->appendRow(rowitems);
friends->appendRow(rowitemsB);
But this gave me the exact same result, John Doe is not present inside Friends, although in both cases, there is an arrow indicating the presence of a child.
Any Idea how to make the same data appear twice?

Answer 1

A QStandardItem can be added once and only once to a QStandardItemModel. Check your debugger log, I'm sure QT writes debug messages saying it's not allowed when you insert the same item twice. By the way, what would return QStandrardItem::index() of an item inserted twice (this method returns row/column position of the item in the QStandardItemModel)?
So you have to create different QStandardItem. You should do like that:
void addEntry( const QString& first, const QString& last, const QString& mail, const QString& tel, QStandardItem* parent )
{
QStandardItem * fn = new QStandardItem(first);
QStandardItem * ln = new QStandardItem(last);
QStandardItem * mail = new QStandardItem(mail);
QStandardItem * phone = new QStandardItem(tel);
QList<QStandardItem*> rowitems;
rowitems << fn << ln << mail << phone;
parent->appendRow(rowitems);
}
...
addEntry( "John", "Doe", "john.doe#gmail.com", "[phone]", work );
addEntry( "John", "Doe", "john.doe#gmail.com", "[phone]", friends );